This invention relates generally to methods and systems of deploying aircraft for use as atmospheric platforms, and more particularly, to communication systems employing aircraft as high-altitude platforms.
Among the many types of aircraft (e.g., balloons, dirigibles, traditional fixed wing airplanes, flying wing airplanes and helicopters), some are capable of high-altitude flight, and some are capable of hovering or maintaining a relatively small flight station (i.e., a small, laterally and vertically limited airspace) with respect to the ground (“stationkeeping”). A limited number of aircraft have been developed for deployment as high-altitude platforms, such as for communication relay systems, which require both high-altitude flying and tight stationkeeping. Such aircraft are preferably solar powered for long flight duration, and are preferably low-speed aircraft to minimize the station size.
Operating from high, suborbital altitudes, such aircraft can operate as communication relay stations between a large number of ground-based and space-based stations. However, the limited number of aircraft that can sustain continuous flight for significant lengths of time typically have limited airspeed ranges, and thus have difficulty in their ability to adapt to changing wind-speeds and weather conditions during flight. Nevertheless, for such aircraft to truly operate as high altitude platforms, they must be able to maintain a tight station in a wide variety of wind speeds and weather conditions.
Given the broad range of functions that a long-duration, tightly stationed, suborbital platform has the potential to perform, it is desirable to design such platforms to be capable of handling larger payloads and power demands, which typically drain resources that could otherwise be directed toward less efficient, but more tightly station-kept flight. Furthermore, because communication system bandwidth and reliability are important, it is preferable that communication systems incorporating such aircraft have redundancy and frequency reuse.
In summary, there exists a definite need for methods of maintaining a tightly kept station in a variety of weather conditions by a long-duration aircraft having flight speed limitations, and a further need for fault tolerant systems that incorporate such aircraft and have high bandwidths. Preferably, using such methods, such an aircraft should be able to operate up to very high, suborbital altitudes for long durations. Importantly, it is desirable for such an aircraft to have the capability for larger payloads and/or power supply requirements. Furthermore, there exists a need for such an aircraft to be inexpensive to build and operate and, furthermore, pollution-free. Various embodiments of the present invention can meet some or all of these needs, and provide further, related advantages.